alter_function(7)

NAME#

ALTER_FUNCTION - change the definition of a function

SYNOPSIS#

ALTER FUNCTION \nname\n [ ( [ [ \nargmode\n ] [ \nargname\n ] \nargtype\n [, ...] ] ) ]
\n
    \naction\n [ ... ] [ RESTRICT ]
ALTER FUNCTION \nname\n [ ( [ [ \nargmode\n ] [ \nargname\n ] \nargtype\n [, ...] ] ) ]
\n
    RENAME TO \nnew_name\n
ALTER FUNCTION \nname\n [ ( [ [ \nargmode\n ] [ \nargname\n ] \nargtype\n [, ...] ] ) ]
\n
    OWNER TO { \nnew_owner\n | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER FUNCTION \nname\n [ ( [ [ \nargmode\n ] [ \nargname\n ] \nargtype\n [, ...] ] ) ]
\n
    SET SCHEMA \nnew_schema\n
ALTER FUNCTION \nname\n [ ( [ [ \nargmode\n ] [ \nargname\n ] \nargtype\n [, ...] ] ) ]
\n
    [ NO ] DEPENDS ON EXTENSION \nextension_name\n
where \naction\n is one of:
\n
    CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT
\n
    IMMUTABLE | STABLE | VOLATILE
\n
    [ NOT ] LEAKPROOF
\n
    [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
\n
    PARALLEL { UNSAFE | RESTRICTED | SAFE }
\n
    COST \nexecution_cost\n
\n
    ROWS \nresult_rows\n
\n
    SUPPORT \nsupport_function\n
\n
    SET \nconfiguration_parameter\n { TO | = } { \nvalue\n | DEFAULT }
\n
    SET \nconfiguration_parameter\n FROM CURRENT
\n
    RESET \nconfiguration_parameter\n
\n
    RESET ALL

DESCRIPTION#

ALTER FUNCTION changes the definition of a function.

You must own the function to use ALTER FUNCTION. To change a function's schema, you must also have CREATE privilege on the new schema. To alter the owner, you must be able to SET ROLE to the new owning role, and that role must have CREATE privilege on the function's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the function. However, a superuser can alter ownership of any function anyway.)

PARAMETERS#

name

argmode

argname

argtype

new_name

new_owner

new_schema

DEPENDS ON EXTENSION extension_name NO DEPENDS ON EXTENSION extension_name

CALLED ON NULL INPUT RETURNS NULL ON NULL INPUT STRICT

IMMUTABLE STABLE VOLATILE

[ EXTERNAL ] SECURITY INVOKER [ EXTERNAL ] SECURITY DEFINER

PARALLEL

LEAKPROOF

COST execution_cost

ROWS result_rows

SUPPORT support_function

This option cannot be used to remove the support function altogether, since it must name a new support function. Use CREATE OR REPLACE FUNCTION if you need to do that.

configuration_parameter value

See SET(7) and Chapter 19 for more information about allowed parameter names and values.

RESTRICT

EXAMPLES#

To rename the function sqrt for type integer to square_root:

ALTER FUNCTION sqrt(integer) RENAME TO square_root;

To change the owner of the function sqrt for type integer to joe:

ALTER FUNCTION sqrt(integer) OWNER TO joe;

To change the schema of the function sqrt for type integer to maths:

ALTER FUNCTION sqrt(integer) SET SCHEMA maths;

To mark the function sqrt for type integer as being dependent on the extension mathlib:

ALTER FUNCTION sqrt(integer) DEPENDS ON EXTENSION mathlib;

To adjust the search path that is automatically set for a function:

ALTER FUNCTION check_password(text) SET search_path = admin, pg_temp;

To disable automatic setting of search_path for a function:

ALTER FUNCTION check_password(text) RESET search_path;

The function will now execute with whatever search path is used by its caller.

COMPATIBILITY#

This statement is partially compatible with the ALTER FUNCTION statement in the SQL standard. The standard allows more properties of a function to be modified, but does not provide the ability to rename a function, make a function a security definer, attach configuration parameter values to a function, or change the owner, schema, or volatility of a function. The standard also requires the RESTRICT key word, which is optional in PostgreSQL.

SEE ALSO#

CREATE FUNCTION (CREATE_FUNCTION(7)), DROP FUNCTION (DROP_FUNCTION(7)), ALTER PROCEDURE (ALTER_PROCEDURE(7)), ALTER ROUTINE (ALTER_ROUTINE(7))